Principal Research Interests

Professor Poirier's research group is concerned with the development and application
of new methods for performing accurate quantum dynamics calculations for molecular
systems. These calculations encompass rovibrational spectroscopy (especially highly
excited states), reactive scattering of molecules in the gas phase and in nanomaterials,
and resonance phenomena (energies, widths, phase shifts). Applications of interest
include hydrogen storage in carbon nanomaterials, dynamics of rare gas clusters, thermal
rate constants pertinent to environmental chemical kinetics, and mass-independent
fractionation of SO2 photodissociation products as a proxy for the Archaen Earth atmosphere.

The methods development research is motivated by the inadequacy of conventional numerical
techniques for dealing with large molecules, insofar as accurate, quantum dynamics
calculations are concerned. Traditionally, the computational effort required scales
exponentially with problem size, as a result of which such calculations have traditionally
been limited to systems with four or fewer atoms. Dr. Poirier's group is exploring
a variety of new approaches that improve the computational efficiency by orders of
magnitude, thereby making it possible to handle a much larger class of systems than
has heretofore been realized. The quantum trajectory approach, inspired by Bohmian
mechanics, incorporates quantum effects into classical-like trajectory simulations.
Symmetrized Weyl-Heisenberg wavelets defeat exponential scaling in basis set methods,
and have been applied to Taylor-expanded-potential systems with up to 27 dimensions,
and adapted for massively parallel computing platforms. Traditional iterative discrete
variable representation methods have also been adapted for massively parallel computers,
with up to tens of thousands of cores.

"Communication: Quantum Mechanics Without Wavefunctions," J. Schiff and B. Poirier, J. Chem. Phys., 136 (3), 031102 (2012). [Number One Most Read JCP Article For January 2012; among top
seven for February and March 2012].